So-called sliding cam valve trains are known in numerous structural designs. To shift the cam part, the axially stationary actuator pin engages in the rotating axial groove whose axial lift forces the cam part to shift on the carrier shaft. In this way, the actuation of the gas exchange valves is switched between two adjacent cam lifts. The shifting of the cam part between the axial positions is performed within the angular range of the camshaft in which all of the cam lifts have no travel, i.e., at the proper time within the common reference circle phase of all cams. The time interval available for this constant angular range decreases with increasing engine speed and accordingly the insertion speed of the actuator pin into the axial groove must also be sufficiently high at high switching rotational speeds to shift the cam part without incorrect switching.
A valve train of the type specified above is known from DE 10 2009 009 080 A1. The two groove tracks do not run circumferentially next to each other, but instead completely one behind the other. This circumferential series connection of the groove tracks is indeed advantageous with respect to the axial installation space requirements of the cam part, but requires an especially quick actuator. This is because, in this case, two retraction processes of the actuator pin into the axial groove and two displacement processes of the cam part in the angle range of the common reference circle phase must be performed. The angle range available for inserting the actuator pin into the axial groove is small accordingly.